Question for home charging install - wire size

[brkaus]

You can see if they would put a block of wood across the next stud bay to mount the evse.

Bummer they won’t put in a sub-panel, but with the pictures it should be an easy change for an electrician.

 

[rstx]

The home isn't fully custom, the builder explicitly bans me from being on the property without a representative from the builder there (they claim due to liability, I can see where that makes sense). I won't actually own the home until I close on it in March.

I feel your pain, years ago when going through something similar with a new house build a buddy of mine that owned low voltage cable company ran some network cable for me prior to sheetrock/close. Builder's electrician found out and said he wouldnt warranty the electrical work with other cable in the house. Even though my guy drilled his own holes etc. Electrician wanted to be paid 10x to do similar work. Was frustrating.

It would be so easy for their electrician to run a short piece of conduit from that big box to another small j box on the adjacent stud. even with no wires in it yet.

 

[Eric33432]

Looks really nice. Super nice installation. Square D QO is a premium panel too.

Looks like they are putting most of the high demand 240 volt circuits on the panel on the right and the EV circuit and one other high demand 240 volt circuit on the left panel.

And running conduit with THHN/THWN-2 for the 100 ampEV circuit!

While done different that I though what they might do, it's even better. Everything split between two 200 amp panels

 

[davewill]

Looks like you'll have a sweet setup. Good thing you've got pictures of the install. With all those cables stapled to the stud on the left, you'll want to be careful. I would heartily recommend that you take the time to take pictures of ALL of the open walls. It can come in handy for so many things down the road. Not only wiring changes, but answer questions about plumbing runs, whether you can cut a door or window into a location or whether a wall is load bearing.

 

[acarney]

Looks like you'll have a sweet setup. Good thing you've got pictures of the install. With all those cables stapled to the stud on the left, you'll want to be careful. I would heartily recommend that you take the time to take pictures of ALL of the open walls. It can come in handy for so many things down the road. Not only wiring changes, but answer questions about plumbing runs, whether you can cut a door or window into a location or whether a wall is load bearing.

I took the advice of you (or someone else) that posted that before and went and got pictures of all the walls. I think I may try to go back today or tomorrow as well because reviewing the pictures there actually looks like one closet area that doesn’t have a low voltage network cable run… or I just can’t see it in the picture. So already might be coming in handy.

 

[arvindm]

Ugh. This is becoming far more stressful than it should. I was as low profile, professional, and clean looking as possible. I also was trying to avoid ripping into walls that were literally days old. They only had one option an “EV Pre-wire” and their management/sales people were… less than familiar with exactly what that option was.

I’m asking to be included during the walk through with their electrician subcontractor “just in case” there were questions with my additions. But really I want to drill down into these questions and see if they can size the wire correctly. I don’t NEED 100 amp. I don’t care if they don’t cut me a discount or anything, I would be fine with 4 AWG run with an appropriate sized breaker.

Looks like the builder has no clue. The prewiring for an EV should be high on his list of things to offer to clients. My suggestion would be to hire a electrician who specializes in EV wiring. Tesla has a list of qualified electricians who can do the job and they are licenced. It is easier to wire for EV when the hose is being built than ripping off walls and doing it afterwards.

 

[ReddykwRun]

What about if they use aluminum wire? Would I then be able to have an electrician use a pigtail to step down to a smaller AWG and copper?

Also, does everyone think there will be enough space behind the wall connector for all this? Ideally I want to slap the wall connector up right over whatever electric box they leave the cable in so it looks as clean as possible...

https://www.smarthomecharge.co.uk/site/assets/files/2207/tesla_charger_installed_1.png <--- That is ideally what I'm going for (though it'll be in a fully enclosed garage).

I'm really hoping I'll be able to show up and chat with their electrician sub before he starts the work and explain to them. I figure this all should be really pretty easy and something they could accommodate, but it's hard when trying to explain to a construction manager that will later try to explain to the subcontractor and doing it all without physically leaving the device with them to just mount up. I really wish they would just let me supply my own device as long as I have it before electrical is scheduled (so I don't hold up schedules) and sign a disclosure saying that they only warranty that the device is wired correctly, not if it is working etc.

100 amp service on a NEW house, Something ain't right. 200 amp service is the standard where I live in South Alabama. And Steer clear of any ALUMINUM WIRE, not acceptable in the house PERIOD. These specs should be in your contract and not left up to chance.

 

[GregD60]

This is an old thread. If you read through the whole thread, you'll see that the issues are resolved, and it's pretty much all good.

 

[acarney]

This is an old thread. If you read through the whole thread, you'll see that the issues are resolved, and it's pretty much all good.

Issue actually wasn't resolved... well, kinda.

I opted to do the panel upgrade, so I have two panels, each about half full now, lol. Plenty of room for upgrades later on.

They installed a 60A breaker in the panel, but it was 2 AWG copper wire. The breaker had to be swapped out because it was a GFCI. I called the same electric company that wired the house. They sent a guy out and he must have stepped down the 2 AWG copper to the correct size for the wall connector. He swapped the 60A breaker for another 60A without GFCI. Wall connector works at 48 amp perfectly. Install is as neat and clean as possible. I still have a junction box that looks pretty rough... but I'll drywall plaster over it and then paint the garage at some point, as long as I don't need to get into the box and wires it'll be fine, I've got the location for down the road if I ever need to.

Also had them swap an inside receptacle to a NEMA 5-20 since it was a dedicated circuit and had them install a ceiling fan outside that was pre-wired. All said and done the install cost for the charger, receptacle swap, and ceiling fan was $366, not bad at all. I still would have preferred the builder to do this and I just move in with it all ready, but this was fairly easy and I'm happy with how it turned out. Loads of capacity for the future and works perfect for me now.

 

[davewill]

If you had opted to do an outlet, you would have needed the GFCI breaker. You could have left it and it would have been fine, but changing it was OK with a wall connector. Nice call on the 5-20. It could serve as an emergency charging back up if you have a mobile connector.

The 2 AWG could come in very handy if you ever decided you needed a second wall connector. You could up the breaker to 80a or 100a depending on what kind of wire and put in a subpanel, then run separate circuits from there, either using power sharing or just splitting the capacity between them evenly.

 

[SageBrush]

Just let your homebuilder's electrician install the 100 amp circuit/feeder. Once that is installed you can either connect it directly to your Tesla Wall Connector (with pigtails as has been previously discussed) or install a small sub panel

Yes.
I know this thread is dead -- I'm only adding for other readers in the future

I would have focused on two things with the builder:

1. Bring the feeder to where I want and at a height I want. Emphasis on feeder here -- 4 wire
2. Leave enough wire in the J-box to easily install a sub-panel

I find it interesting that the builder called the option an "EV" something or another when it is just a feeder

 

[SageBrush]

I still have a junction box that looks pretty rough... but I'll drywall plaster over it and then paint the garage at some point

If that box has wires in it, it must be accessible to meet NEC. Put a cover on it instead

 

[davewill]

If that box has wires in it, it must be accessible to meet NEC. Put a cover on it instead

Good catch! Yes, drywalling over the junction box is a big problem. A future electrician will be scratching their heads when they can't see where the wire changes size. Also, if one of those connections goes bad, no one can inspect them to figure out the problem. Finally if the drywall is exposed to the interior of the box, it can be a fire hazard.

 

[SageBrush]

A future electrician will be scratching their heads when they can't see where the wire changes size.

Ah yes ... about that solution. If the breaker is sized to the smaller wire then fine. Otherwise, the tap rules come into play. See 240.4 towards the end

I'm a huge fan of sub-panels but a tap with a fuse disconnect before the hardwired EVSE is not bad

 

[sllowsteady]

it is great if you terminate at a sub-panel, as has been suggested. If you have the builder do that you can add a 60A circuit for your wall connector, plus another one later on (using built in power sharing), and still be able to have multiple 120v circuits. Running a circuit from a sub-panel to a wall connector is often an easy DIY project.